A system for condition monitoring and fault diagnosis includes a data collection function that acquires time histories of selected variables for one or more of the components, a pre-processing function that calculates specified characteristics of the time histories, an analysis function for evaluating the characteristics to produce one or more hypotheses of a condition of the one or more components, and a reasoning function for determining the condition of the one or more components from the one or more hypotheses.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A continuous health monitoring system comprising: a non-transitory data collection function that acquires unparameterized time histories of selected mechanical performance variables for one or more components during component operations; a non-transitory pre-processing function that calculates specified characteristics of each of the unparameterized time histories by independently characterizing each unparameterized time history of the selected mechanical performance variables; a non-transitory analysis function for evaluating the specified characteristics of each of the unparameterized time histories to produce one or more hypotheses of a condition of the one or more components; and a non-transitory reasoning function for determining the condition of the one or more components from the one or more hypotheses, wherein the data collection, pre-processing, and analysis functions operate in parallel with the component operations.
2. The system of claim 1 , wherein the selected mechanical performance variables include a difference between a predicted torque and a measured torque of the one or more components.
3. The system of claim 2 wherein: the non-transitory pre-processing function operates to compute metrics using an operational torque from the unparameterized time histories and a torque baseline; and the non-transitory analysis function operates to evaluate whether the computed metrics exceed predetermined threshold values to produce one or more hypotheses of a condition of the one or more components.
4. The system of claim 3 , wherein the torque baseline used by the non-transitory pre-processing function is acquired from a component torque model.
5. The system of claim 1 , wherein the selected mechanical performance variables include a difference between a predicted current and a measured current of the one or more components.
6. The system of claim 5 , wherein: the non-transitory pre-processing function operates to compute metrics using an operational current from the unparameterized time histories and a current baseline; and the non-transitory analysis function operates to evaluate whether the computed metrics exceed predetermined threshold values to produce one or more hypotheses of a condition of the one or more components.
7. The system of claim 5 , wherein the current baseline used by the non-transitory pre-processing function is acquired from a component current model.
8. The system of claim 1 , wherein the selected mechanical performance variables include a tracking error of the one or more components.
9. The system of claim 8 , wherein the non-transitory data collection function acquires the unparameterized time histories for predefined component locations and the non-transitory pre-processing function computes an integral of the absolute value of a tracking error as at least one of the specified characteristics.
10. The system of claim 8 , wherein the non-transitory data collection function acquires the unparameterized time histories over a predetermined sequence of component moves and the non-transitory pre-processing function computes an integral of the square of the tracking error as at least one of the specified characteristics.
11. The system of claim 1 , wherein at least one of the components includes a motor and the selected mechanical performance variables include at least an actual voltage, current, and velocity of the motor.
12. The system of claim 11 , wherein the non-transitory pre-processing function calculates a modeled current from the actual voltage and velocity, calculates a difference between the actual and modeled current, and determines a maximum variation between the actual and modeled current as at least one of the specified characteristics.
13. The system of claim 12 , wherein the non-transitory analysis function compares the maximum variation with an allowable threshold, and the non-transitory reasoning function utilizes results from the non-transitory analysis function over several instances of data collection to confirm a change in the specified characteristics.
14. The system of claim 1 , wherein at least one of the selected mechanical performance variables includes an incremental position of the one or more components recorded upon receiving an index pulse from an incremental encoder.
15. The system of claim 14 , wherein the non-transitory analysis function computes a difference between incremental positions at successive index pulses and determines if the difference is within a tolerance of a multiple of the number of incremental counts per revolution of the incremental encoder.
16. The system of claim 1 , wherein at least one of the selected mechanical performance variables includes an absolute position of the one or more components recorded by an absolute encoder.
17. The system of claim 16 , wherein the non-transitory analysis function computes a difference between the absolute position and an actual position of the one or more components.
18. The system of claim 16 , wherein the non-transitory analysis function computes a difference between the absolute position and an average actual position of the one or more components if the absolute encoder is stationary.
19. The system of claim 1 , wherein the one or more components includes a belt and at least one of the selected variables includes a tension of the belt.
20. The system of claim 1 , wherein at least one of the selected mechanical performance variables includes a position and acceleration measurements at various points on the one or more components.
21. The system of claim 1 , wherein at least one of the selected mechanical performance variables includes a position and acceleration measurements at various points on the one or more components and the non-transitory pre-processing function calculates a power spectrum of the position and acceleration measurements as one of the specified characteristics.
22. The system of claim 1 , wherein at least one of the selected mechanical performance variables includes a temperature of the one or more components.
23. The system of claim 22 , wherein the non-transitory analysis function compares the temperature with a threshold as at least one of the specified characteristics.
24. The system of claim 23 , wherein the non-transitory reasoning function determines the condition of one or more cooling fans from the one or more hypotheses produced by the non-transitory analysis function.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
November 5, 2018
November 24, 2020
Browse 5M+ US patents with plain-English claim translations and AI-generated analysis.